UNITED STATES.- Extreme fire danger prompted officials to shut down a sprawling forest that includes some of Colorado’s most stunning mountains in a region that attracts tourists from around the world, a rare tactic also being used in neighboring states as the U.S. Southwest struggles with severe drought.

National forests and parks in Arizona and New Mexico have already been shut down as precautions.

San Juan National Forest officials in southwestern Colorado closed hundreds of miles of trails and thousands of miles of back roads to hikers, bikers, horseback riders and campers Tuesday to prevent the possibility of an abandoned campfire or any other spark from starting a wildfire. It’s the first full closure of a national forest in Colorado since 2002, which was another very dry year.

The closure will remain until sufficient precipitation eases the fire danger.

The move comes as the residents of over 2,000 homes have been forced to evacuate because of a fire that started June 1 in the forest that has burned about 31 square miles (about 80 square kilometers). It is 15 percent contained. Another fire nearby has burned about 4 square miles (10 square kilometers). Authorities are still investigating how the fire started.

No homes have been lost although the fire came close to buildings Sunday night, authorities said. Fire managers credited advance fire mitigation work by homeowners for helping firefighters save the structures.

Much of the U.S. West is experiencing some level of drought and the Four Corners region — where Arizona, New Mexico, Utah and Colorado meet — is at the center of a large patch of exceptional drought.

In New Mexico, the Santa Fe National Forest, along with portions of three national park sites, closed June 1 because of the fire danger. The Santa Fe forest is among New Mexico’s most popular getaways.The U.S. Forest Service also is planning to bar recreation in a handful of ranger districts in the Cibola National Forest outside of Albuquerque beginning Friday.

Portions of national forests in Arizona were also closed in late May because of severe fire conditions.

Full forest closures are not common and the Forest Service stresses they’re only done as a last resort. The Coconino National Forest in Arizona shut down completely because of fire danger in 2006 for nine days. A 2002 shutdown lasted nine weeks, including both Memorial Day and July 4 holidays, and other national forests had closures that year.

Colorado’s latest closure will also bar non-recreational uses, although ranchers, for example, who use some of the forest’s over 2,800 square miles (7,252 square kilometers) for grazing will be able to seek exemptions, San Juan National Forest spokeswoman Cam Hooley said.